4zhj

Crystal Structure of the Catalytic Subunit of Magnesium Chelatase

spinqualitylabelsall models 4zhj, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4zhj is a 2 chain structure with sequence from Syny3. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: chlH (SYNY3) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Tetrapyrroles, including haem and chlorophyll, play vital roles for various biological processes, such as respiration and photosynthesis, and their biosynthesis is critical for virtually all organisms. In photosynthetic organisms, magnesium chelatase (MgCh) catalyses insertion of magnesium into the centre of protoporphyrin IX, the branch-point precursor for both haem and chlorophyll, leading tetrapyrrole biosynthesis into the magnesium branch(1,2). This reaction needs a cooperated action of the three subunits of MgCh: the catalytic subunit ChlH and two AAA(+) subunits, ChlI and ChlD (refs 3-5). To date, the mechanism of MgCh awaits further elucidation due to a lack of high-resolution structures, especially for the approximately 150 kDa catalytic subunit. Here we report the crystal structure of ChlH from the photosynthetic cyanobacterium Synechocystis PCC 6803, solved at 2.5 A resolution. The active site is buried deeply inside the protein interior, and the surrounding residues are conserved throughout evolution. This structure helps to explain the loss of function reported for the cch and gun5 mutations of the ChlH subunit, and to provide the molecular basis of substrate channelling during the magnesium-chelating process. The structure advances our understanding of the holoenzyme of MgCh, a metal chelating enzyme other than ferrochelatase. Crystal structure of the catalytic subunit of magnesium chelatase.,Chen X, Pu H, Fang Y, Wang X, Zhao S, Lin Y, Zhang M, Dai HE, Gong W, Liu L Nat Plants. 2015 Aug 24;1:15125. doi: 10.1038/nplants.2015.125. PMID:27250678 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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